Tennis star Anna Kournikova of Russia recreates a legendary Marilyn Monroe pose during the filming of the adidas climacool commercial on location in Los Angeles. (Photo by CLIVE BRUNSKILL/Getty Images). 11 Mar. 2002

A Thorneycroft motor van as used during World War I. (Photo by Topical Press Agency/Getty Images). August 1914

Female soldiers march in formation in St Petersburg' s Palace Square during a rehearsal of a Victory Day military parade marking the 72 nd anniversary of the victory over Nazi Germany in the 1941-1945 Great Patriotic War, the Eastern Front of World War II, on May 5, 2017. (Photo by Peter Kovalev/TASS)

A view of the cemetery where the graves of the soldiers who lost their lives in the Russia-Ukraine war are located as daily life continues in shadow of war in Kursk, Russia on August 18, 2024. (Photo by Vladimir Aleksandrov/Anadolu via Getty Images)

Former Division I volleyball star Kayla Simmons in the second decade of July 2023 wowed her fans in a stunning bikini snap on social media. Kayla has been called the world's sexiest volleyball star. (Photo by @kaylasimmmons/Instagram)

Former Coronation Street star Helen Flanagan was the subject of more mum shaming as she posts eye-popping snap. The I'm A Celeb: South Africa star took to social media with a risque snap as she enjoyed a London getaway in the first decade of September 2023. (Photo by @hjgflanagan/Instagram)

A cenote is a natural phenomenon, a sinkhole in the Earth’s surface. The Yucatan Peninsula in Mexico has an estimated 7,000 cenotes because it is primarily made up of porous limestone. For millions of years, rainfall slowly ate away at the limestone and a huge system of underground caves and caverns was formed. Many filled with water from rain or from the underground water table. When the roof of a water filled cave collapses, a cenote is born. The water found in a cenote may be fresh water, salt water, or both. Structurally it may be completely open, like a lake, almost completely closed with just a small opening at the top, or somewhere in between.

A tattoo of Captain America drawn by artist Sean Karon on the leg of client Ron Raucci at the Hampton Roads Tattoo Festival in Virginia, on March 2, 2012. The tattoo was completed from start to finish in one five-and-a-half hour session and won the prestigious “tattoo of the day” contest. (Photo by Jason Reed/Reuters)